# NTSB ANC14CA012: Douglas DC-6, N100CE, Nuiqsut, AK, November 25, 2013 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: November 25, 2013, 10:21 local (14:21 UTC) - Place: Nuiqsut, AK - Coordinates: 70.344169, -150.944717 - Nearby events: https://openairdocs.org/map.md?lat=70.3442&lon=-150.9447&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report April 23, 2014 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA - NTSB case key (mKey): 88574 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC14CA012 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/88574/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=88574 - Page: https://openairdocs.org/ntsb/ANC14CA012 ## Probable cause A load shift during takeoff, which resulted in substantial damage to the aft bulkhead and associated structures. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Equipment/furnishings: cargo compartments](https://openairdocs.org/ntsb-findings/01022550): Aircraft › Aircraft systems · Incorrect use/operation (probable cause); cases with it: [Douglas C-118A, 1 case](https://openairdocs.org/ntsb-findings/01022550/cases.md?model=3021710), [All aircraft, 2 cases](https://openairdocs.org/ntsb-findings/01022550/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft loading event](https://openairdocs.org/ntsb-events/010); cases with it: [Douglas C-118A, 1 case](https://openairdocs.org/ntsb-events/010/sequence.md?model=3021710), [All aircraft, 84 cases](https://openairdocs.org/ntsb-events/010/sequence.md) - [Takeoff: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [Douglas C-118A, 1 case](https://openairdocs.org/ntsb-events/900/sequence.md?model=3021710), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) ## Analysis According to the operator, the purpose of the short, 22 minute flight was to deliver a load of oversized, oil drilling tools to a remote oil production site. The flightcrew reported that shortly after takeoff the first officer noticed that the airplane's elevator control movements appeared to be "momentarily stiff." While en route to the destination, the flight engineer was asked to inspect the cargo, and he subsequently discovered that two of the four, 31-foot long oil drilling tools had shifted aft, damaging the aft pressure bulkhead. The captain did not declare an emergency, and the airplane landed at the destination without incident. A postflight inspection revealed substantial damage to the aft pressure bulkhead assembly, as well as various frames, stringers and structural longerons. In addition, several attachments for the elevator flight control pulleys and flight control cable guides were damaged. The operator noted that the airplane's pressurization system had been removed years ago, when the airplane was converted to a cargo configuration. The operator reported that after loading the airplane, just before departure, the crew inspected the five nylon strapping mechanisms that secured the four drilling tools to the floor of the airplane. The crew reported that all five of the nylon straps were tight before departure, but gathered that one or more had loosened slightly during taxi and takeoff, allowing two of the tools to shift aft during takeoff. The crew also noted that the drilling tools were covered with ice and snow, which likely aided in the tools sliding along the aluminum, diamond plate-covered floor of the airplane. ## Factual narrative According to the operator, the purpose of the short, 22 minute flight was to deliver a load of oversized, oil drilling tools to a remote oil production site. The flightcrew reported that shortly after takeoff the first officer noticed that the airplane's elevator control movements appeared to be "momentarily stiff." While en route to the destination, the flight engineer was asked to inspect the cargo, and he subsequently discovered that two of the four, 31-foot long oil drilling tools had shifted aft, damaging the aft pressure bulkhead. The captain did not declare an emergency, and the airplane landed at the destination without incident. A postflight inspection revealed substantial damage to the aft pressure bulkhead assembly, as well as various frames, stringers and structural longerons. In addition, several attachments for the elevator flight control pulleys and flight control cable guides were damaged. The operator noted that the airplane's pressurization system had been removed years ago, when the airplane was converted to a cargo configuration. The operator reported that after loading the airplane, just before departure, the crew inspected the five nylon strapping mechanisms that secured the four drilling tools to the floor of the airplane. The crew reported that all five of the nylon straps were tight before departure, but gathered that one or more had loosened slightly during taxi and takeoff, allowing two of the tools to shift aft during takeoff. The crew also noted that the drilling tools were covered with ice and snow, which likely aided in the tools sliding along the aluminum, diamond plate-covered floor of the airplane. ## Aircraft - Registration: [N100CE](https://openairdocs.org/aircraft/N100CE), registered now, S/N 44662, built 1953 (OpenAirDocs) - Reported make and model: DOUGLAS DC-6 - Registry model: [Douglas C-118A](https://openairdocs.org/model/douglas-c-118a) (registry code 3021710) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-2800 series](https://openairdocs.org/engine/pratt-whitney-r-2800-series) (registry code 52026, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 44662 - Year built: 1953 - Airframe hours: 32042 - Engines: Pratt & Whitney R-2800 2000 horsepower reciprocating - Damage: Substantial damage - Flight: Part 121 - Operator: Tatonduk Outfitters Ltd, doing business as Everts Air Cargo - Registered owner: Tatonduk Outfitters Ltd - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, November 21, 2013 - Departed: AK15, Nuiqsut, AK - Destination: PASC, Deadhorse, AK - Flight plan: IFR - Airport: AK15, Alpine Airstrip, runway 03, 5,005 × 100 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; airline transport, flight engineer; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review November 1, 2013; seat: left; restraint: 4-point; flight hours: 14,100 total, 12,100 in this make and model, 9,100 as pilot in command, 115 in the last 90 days, 47 in the last 30 days, 2 in the last 24 hours - Co-pilot; age 52; injuries: none; airline transport, flight engineer; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review June 13, 2013; seat: right; restraint: 4-point; flight hours: 4,516 total, 968 in this make and model, 160 in the last 90 days, 45 in the last 30 days, 2 in the last 24 hours - Flight engineer; injuries: none; flight engineer, commercial; seat: center; restraint: 4-point ## Weather - Conditions: Visual (VMC), Night - Wind: 210° at 10 knots - Visibility: 4 statute miles - Lowest ceiling: 1,100 ft overcast - Temperature: -6 °F, dew point -8 °F - Altimeter: 30.32 inHg ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20131125025379A](https://openairdocs.org/incident/20131125025379A), Nov 25, 2013: Douglas C-118A, Deadhorse, AK, Substantial damage. During an all cargo flight from Alpine strip, Alaska to Deadhorse Alaska on 11/25/2013 the aircraft experienced a cargo load shift resulting in damage to the… ## Docket (2 files) The files NTSB released with the investigation on April 7, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=88574. 767 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 589 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40411027&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Letter from Everts Air Cargo (item 2, .PDF, 178 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40411028&FileExtension=.PDF&FileName=Letter%20from%20Everts%20Air%20Cargo-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.